The invention relates to containers in general, particularly to containers for flowable media of pasty or liquid consistency, and more particularly to improvements in collapsible containers. Still more particularly, the invention relates to improvements in containers of the type wherein a collapsible structure confines a deformable envelope and the envelope has a sealable opening for admission or evacuation of flowable media.
It is already known to replace conventional rigid metallic cans (such as gasoline cans) with collapsible containers which occupy little room in collapsed condition and can be erected or expanded preparatory to admission of selected quantities of flowable media into their internal spaces. Such collapsible containers are often used for storage of highly viscous or pasty, flowable solid or readily flowable liquid substances.
Certain presently known collapsible containers are assembled of deformable envelopes (hereinafter called bags for short) and collapsible boxes of corrugated board. The box surrounds and confines the bag, and the bag is assembled of two mirror symmetrical halves which are welded to each other to define a cavity for reception of a flowable medium. The halves of the bag are made from a suitable plastic material by deep drawing. When not in use, several bags can be telescoped into or otherwise assembled with each other independently of the boxes to occupy little room in storage and/or during transport.
Another conventional collapsible container, known as "bag in box", is used primarily for storage of beverages and includes a bag which is made of plastic foil and is confined in a box of corrugated board. The box can be erected around the bag to permit convenient filling as well as to protect the filled bag during storage or in transit.
A drawback of the aforedescribed conventional collapsible containers is that they cannot be readily manipulated and cannot be readily filled in automatic filling machines. This is due to the fact that the deformable bags of conventional two-piece containers cannot be conveniently attached to the spout of an automatic metering, filling or decanting machine. All this contributes to higher cost of the filled containers.
Published German patent application No. 30 16 466 discloses a two-piece collapsible container which employs a bag made from a length of flexible thermally welded tubular plastic material within a collapsible and erectable cardboard box. The bag is formed with an opening which is sealable by a closure. The opening is defined by a rigid mouthpiece which is supported by a plate having projections which are receivable in complementary notches provided therefor in the internal surface of the box. This ensures that the inlet of the mouthpiece is maintained in a predetermined position and orientation as soon as the plate is properly installed in and is properly secured to the box. Thus, the plate is intended to perform several functions including supporting the mouthpiece, maintaining the mouthpiece in a predetermined orientation, and coupling the corresponding portion of the bag to the box. The main purpose of the plate is to facilitate the admission of flowable material into the bag. This container exhibits the drawback that erection of the cardboard box and attachment of the plate to the notched portion of the box take up too much time. It is further necessary to close the bottom of the box before the latter can properly receive and confine the bag. In addition, the material (cardboard) of the box is likely to be moistened during admission of a liquid medium into the bag, as a result of leakage of liquid medium from the confined bag and/or as a result of leakage of liquid medium from the bag in an adjoining container if two or more containers are stored on a shelf or in a larger receptacle.
Published German patent application No. 24 37 670 discloses a collapsible container which is used for reception of arrays of flowers or for reception of soil if the container is to be used as a flower pot. The container is fluidtight and is assembled of a collapsible and erectable box in the interior of a deformable outer bag. The outer bag is made of plastic foil. Erection of the confined box results in enlargement of the internal space of the outer bag so that the resulting suction in the bag entails an inward folding of overhanging portions of the bag. This is intended to result in the making of a twin-walled bag, namely a bag having an inner wall within the erected box and an outer wall surrounding the erected box. When erected, the box constitutes a hollow body having a polygonal cross-sectional outline and being confined between loosely hanging inner and outer walls of the bag. The top of the container is open and its bottom wall can support soil for the roots of a relatively small plant or a piece of foamed plastic material which is supposed to support an array of flowers. The just described container is used primarily as a substitute for flower pots or flower trays but is not suitable for confinement of pastes, other viscous substances, liquids, flowable solid materials or similar media which must be fully confined during storage and/or during transport.